16

Figure 17. Read operation

1

2

3

4

5

6

7

8

0

A

6

A

5

A

4

A

3

A

2

A

1

A

0

9

10

11

12

13

14

15

16

D

6

D

5

D

4

D

3

D

2

D

1

D

0

D

7

SCLK

Cycle #

SCLK

MOSI

MISO

NCS

Figure 15. MOSI setup and hold time

Write Operation

Write operation, defined as data going from the micro-

controller to the ADNS-3090, is always initiated by the

micro-controller and consists of two bytes. The first byte

contains the address (seven bits) and has a “1” as its MSB

to indicate data direction. The second byte contains

the data. The ADNS-3090 reads MOSI on rising edges

of SCLK.

Figure 18. MISO delay and hold time

Read Operation

A read operation, defined as data going from the

ADNS-3090 to the micro-controller, is always initiated

by the micro-controller and consists of two bytes. The

first byte contains the address, is sent by the micro-

controller over MOSI, and has a “0” as its MSB to indicate

data direction. The second byte contains the data and is

driven by the ADNS-3090 over MISO. The sensor outputs

MISO bits on falling edges of SCLK and samples MOSI bits

on every rising edge of SCLK.

NOTE:

The 250 ns minimum high state of SCLK is also the minimum

MISO data hold time of the ADNS-3090. Since the falling

edge of SCLK is actually the start of the next read or write

command, the ADNS-3090 will hold the state of data on

MISO until the falling edge of SCLK.

SCLK

MOSI

A

6

A

5

A

2

A

3

A

4

A

0

A

1

D

7

D

4

D

5

D

6

D

0

D

1

D

2

D

3

15

7

8

9

10

11

12

13

14

16

2

3

4

5

6

1

1

1

1

A

6

2

SCLK

MOSI

NCS

MISO

MOSI Driven by Micro-Controller

SCLK

MISO

Figure 16. Write Operation

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PixArt Imaging Inc.

PixArt Imaging Inc.